Addressing media in the national capital, Singh said that Guru was hanged at 8 a.m. on Saturday morning in Delhi's Tihar Jail.

"He was hanged at 8 o' clock this morning. The president rejected his petition on February 3," said the Union Home Secretary, adding: "The law and justice is taking its course."

Speaking to a news channel, the Home Secretary said: "The decision on Afzal Guru's body will be taken as per the jail manual. Afzal Guru will be buried with full religious rites inside the jail. We are not apprehending any law and order problem in Kashmir. The Jammu and Kashmir Chief Minister was kept in the loop."

He further said: "We did an investigation. As soon as the President rejected his petition, further steps according to the jail manual were taken up. I repeat myself; it was law taking its course. It's a rule of the law. We don't announce our steps word by word. The J and K Police has taken some security measures," Singh said.

In the wake of his hanging, curfew has been imposed in several areas of Jammu and Kashmir in anticipation of protests. The army is on high-alert in the state.

Guru was given the death sentence by the Supreme Court in 2004. His hanging was earlier scheduled for October 2006, but was suspended or stayed after his wife had filed a mercy petition on his behalf.

In December 2001, five heavily-armed terrorists drove into the Parliament complex and opened fire. Nine people were killed, most of them security personnel. All five terrorists were killed.

At that time, proceedings in Parliament was adjourned even as several lawmakers were inside. A few days later, Guru was arrested on the charge that he had masterminded the terror strike.

The main opposition BJP has repeatedly questioned the delay in Guru's execution, and its leaders last questioned the government in Parliament on the 11th anniversary of the attack (December 13, 2012).

Guru's execution comes almost three months after Pakistani terrorist Ajmal Kasab was hanged in Pune's Yeravada Jail for his role in the terror strikes in Mumbai between November 26 and 29, 2008.

Guru hailed from Sopore in Kashmir.

Separatist groups in Kashmir had earlier warned of retaliation if Guru was executed. Jammu and Kashmir Chief Minister Omar

Abdullah had repeatedly stressed that it could have serious repercussions on his state.